Moved some duplicated node movement related calculations into the _inter_tree_move_and_close_gap method
Moved some duplicated node movement related calculations into the _inter_tree_move_and_close_gap method

git-svn-id: 8aeb0e65b862530f646eab05f68768ebd9f37f99@40 7eea2103-5a42-0410-ac78-6383eb04bdbf

batiste/django-mptt,batiste/django-mptt,brosner/django-mptt